Thermal printers that use precut sheets of dye receiver media typically provide a stack of many such media sheets in a receiver supply tray. A receiver picker mechanism presses against the top of the receiver supply stack to urge a dye receiver sheet from the stack into the printer. During a printing operation, the receiver picker mechanism drives at least one wheel against the stack of sheets in the receiver supply tray thereby urging a dye receiver sheet along a receiver transport path.
Prior art picker mechanisms typically use a conventional flat wheel shape or a tordoidal wheel shape to drive the dye receiver sheet. The picker wheel is mounted on a picker wheel shaft oriented perpendicular to a feed direction in which the dye receiver is driven. It is possible for the dye receiver sheet to enter the receiver transport path skewed or offset from an orientation which is rectilinear and aligned to the receiver transport path. This can occur when the dye receiver sheet on the receiver supply stack is skewed or misaligned to the feed direction, or when the receiver picker mechanism is angled or misaligned to the feed direction. Tight tolerances and complex assembly procedures may address the receiver picker mechanism orientation problems, but variability in how the user inserts the dye receiver into the printer cannot be controlled easily. Skewed or offset receiver sheet orientations result in printed images which are not rectilinear and centered on the receiver, producing inferior print quality. Accordingly, it will be appreciated that it would be highly desirable to have a picker mechanism which compensates for the variability in how an operator loads the dye receiver media, and which corrects skewing of the media.